major reference

...another element, a halogen is itself reduced; i.e., the oxidation number 0 of the free element is reduced to −1. The halogens can combine with other elements to form compounds known as
halides—namely, fluorides, chlorides, bromides, iodides, and astatides. Many of the
halides may be considered to be salts of the respective hydrogen
halides, which are colourless gases at room...

actinoid compound structure

...and alkali double sulfates of the actinoids are also insoluble, with many of each having identical crystal structures, or being isostructural. The chlorides, bromides, and iodides (i.e., the
halides) of the actinoids are, for the most part, isostructural for any one
halide, and the structure type can be predicted from a knowledge of the ionic radius. The solubility of these
halides in...

ceramics

...fluoride (CaF), and strontium fluoride (SrF
2) have been used for erosion-resistant infrared radomes, windows for infrared detectors, and infrared laser windows. These polycrystalline
halide materials tend to transmit lower wavelengths than oxides, extending down to the infrared region; however, their grain boundaries and porosity scatter radiation. Therefore, they are best used...

copper compounds

Cuprous chloride, CuCl, can be prepared by treating metallic copper and cuprous oxide with hydrochloric acid or by treating metallic copper and cupric chloride with hydrochloric acid. The hydrochloric acid solution of cuprous chloride readily absorbs carbon monoxide and acetylene and is used for this purpose in gas analysis. Cupric chloride, CuCl
2, can be prepared by dissolving...

displacement reaction

A hydroxide ion can displace a
halide ion from a primary alkyl
halide (RCH
2X, where X is a halogen) to give an alcohol. This displacement reaction is not frequently used to synthesize alcohols, however, because alkyl
halides are more commonly synthesized from alcohols rather than vice versa.

ion-exchange equilibrium

The selectivity sequence for
halide ions in resins with quaternary-ammonium fixed ions is fluoride, chloride, bromide, and iodide, with fluoride being held the most weakly. This resembles the cation selectivity order, in which the smallest ion also is held most weakly. On the other hand, the differences between the various ions in degree of attachment to the resin is much greater in the series...

rare-earth elements

The three main stoichiometries in the
halide systems (X = fluorine, chlorine, bromine, and iodine) are tri
halides (RX
3), tetra
halides (RX
4), and reduced
halides (RX
y,
y < 3). The tri
halides are known for all the rare earths except europium. The only tetra
halides known are the RF
4 phases, where R = cerium,...

X-ray detection

The first X-ray detector used was photographic film; it was found that silver
halide crystallites would darken when exposed to X-ray radiation. Alkali
halide crystals such as sodium iodide combined with about 0.1 percent thallium have been found to emit light when X rays are absorbed in the material. These devices are known as scintillators, and when used in conjunction with a photomultiplier...